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For ESD test (HBM)
. U8 a7 L% G7 B* D7 L& `The following are the test combination:1 t! X3 d1 s% @/ U( g
1. Power to Power$ X) ]9 p( g' k7 H
2. Power to Ground7 [+ q' n: F% d. u
3. IO to Power
. I3 v- v6 P8 W- S$ \$ u9 r4. Io to Ground
* p/ h U3 S3 I5. IO to IO
+ F h8 k# C% m* _5 m7 w* q(different power domain need to be treated as different power. For ground usually you can treat as one group_silicon use substrate as common ground. But if you measure two different ground pin/ball > 2ohms. It should be seperated as 2 grond.)9 _! B% j2 l% x$ B0 |
. f2 t, R3 c; J, q. z. \$ bthe total zap time fomula will be~ 2(+/- polarity) X (IO#X(P#+G#)+IO#+P#X(P#-1)X(P#-2)X...X1+P#XG)% `7 N% C5 h0 k6 E& Q
For example: You have IO1/IO2/IO3/P1/P2/G1& g8 @) k) e; ]. @7 x' }2 S
2x((3X(2+1)+3+2X1+2X1)=25(multiple the zap interval)* O. @; h$ p/ M% H7 S9 P. [ X" R
So for high pin count it will take a lot of time. But it won't take more than a week(for one chip). ) V8 M% z! r" m
5 B; b4 B) ?9 s/ y {For your reference. |
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